Our custom-fit cowl plugs are constructed of sturdy closed cell foam, with a melting point of 265 degrees. The cowl plug foam does not absorb water and is UV resistant which means the foam does not fade or breakdown which allows for a long service life. The cowl plugs are connected by a 38" x 1/8" black cord. Each cowl plug has a woven REMOVE BEFORE FLIGHT safety streamer that is easily noticed by the pilot during the preflight inspection.